The objective of this proposal is to correlate morphologic abnormalities in excised human lungs from primarily young (less than 40 years of age) asymptomatic individuals with known lung disease, with test of early chronic obstructive pulmonary disease (COPD). Postmortem physiology tests such as static pressure volume curves, single breath nitrogen washouts, maximal expiratory flow volume courves with various gas mixtures, maximal mid expiratory flow, FEV1 and FVC values, central and peripheral airway resistance. Physiologic data will be correlated with careful morphometric measurements of whole lung anatomy. This study will establish the anatomic basis for tests commonly believed to identify "small airway disease". The detailed functional assessment of relatively young human lungs will add to our knowledge of the significance of mild or early lesions of airway and alveoli.